From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751191Ab0AMKbD (ORCPT ); Wed, 13 Jan 2010 05:31:03 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755589Ab0AMKa7 (ORCPT ); Wed, 13 Jan 2010 05:30:59 -0500 Received: from hera.kernel.org ([140.211.167.34]:58934 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755588Ab0AMKa6 (ORCPT ); Wed, 13 Jan 2010 05:30:58 -0500 Date: Wed, 13 Jan 2010 10:30:19 GMT From: tip-bot for Frederic Weisbecker Cc: linux-kernel@vger.kernel.org, paulus@samba.org, acme@redhat.com, hpa@zytor.com, mingo@redhat.com, peterz@infradead.org, fweisbec@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, acme@redhat.com, paulus@samba.org, linux-kernel@vger.kernel.org, fweisbec@gmail.com, peterz@infradead.org, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <1262227945-27014-1-git-send-regression-fweisbec@gmail.com> References: <1262227945-27014-1-git-send-regression-fweisbec@gmail.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf: Stop stack frame walking off kernel addresses boundaries Message-ID: Git-Commit-ID: c2c5d45d46c8c0fd34291dec958670ad4816796f X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.3 (hera.kernel.org [127.0.0.1]); Wed, 13 Jan 2010 10:30:19 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: c2c5d45d46c8c0fd34291dec958670ad4816796f Gitweb: http://git.kernel.org/tip/c2c5d45d46c8c0fd34291dec958670ad4816796f Author: Frederic Weisbecker AuthorDate: Thu, 31 Dec 2009 03:52:25 +0100 Committer: Ingo Molnar CommitDate: Wed, 13 Jan 2010 09:32:54 +0100 perf: Stop stack frame walking off kernel addresses boundaries While processing kernel perf callchains, an bad entry can be considered as a valid stack pointer but not as a kernel address. In this case, we hang in an endless loop. This can happen in an x86-32 kernel after processing the last entry in a kernel stacktrace. Just stop the stack frame walking after we encounter an invalid kernel address. This fixes a hard lockup in x86-32. Signed-off-by: Frederic Weisbecker Cc: Peter Zijlstra Cc: Arnaldo Carvalho de Melo Cc: Paul Mackerras LKML-Reference: <1262227945-27014-1-git-send-regression-fweisbec@gmail.com> Signed-off-by: Ingo Molnar --- arch/x86/kernel/dumpstack.c | 14 ++++++++------ 1 files changed, 8 insertions(+), 6 deletions(-) diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c index c56bc28..6d81755 100644 --- a/arch/x86/kernel/dumpstack.c +++ b/arch/x86/kernel/dumpstack.c @@ -123,13 +123,15 @@ print_context_stack_bp(struct thread_info *tinfo, while (valid_stack_ptr(tinfo, ret_addr, sizeof(*ret_addr), end)) { unsigned long addr = *ret_addr; - if (__kernel_text_address(addr)) { - ops->address(data, addr, 1); - frame = frame->next_frame; - ret_addr = &frame->return_address; - print_ftrace_graph_addr(addr, data, ops, tinfo, graph); - } + if (!__kernel_text_address(addr)) + break; + + ops->address(data, addr, 1); + frame = frame->next_frame; + ret_addr = &frame->return_address; + print_ftrace_graph_addr(addr, data, ops, tinfo, graph); } + return (unsigned long)frame; } EXPORT_SYMBOL_GPL(print_context_stack_bp);